Specially equipped measuring aircraft are used for identifying trace gases and aerosols in the atmosphere. The term aerosols refers to solid and/or liquid particles in the air. One distinguishes between aerosols in the form of Aitken particles with a size of less than about 0.1 μm and the so-called fine aerosols of the accumulation mode with sizes between about 0.1 μm and about 2.5 μm. Particles larger than about 2.5 μm are referred to as coarse aerosol. Solid dust particles can be created during the mechanical destruction of solid material and usually have diameters larger than about 1 μm. The most important sources for dust aerosols are desert and arid environments. Volcanic eruptions also emit about 33*106 tons of aerosols annually into the atmosphere. The importance of volcanic dust results from the fact that a large quantity of dust aerosols and fly ash can be locally thrown into high altitudes of the atmosphere and therefore represent, if applicable, a hazard to air traffic. However, there is no wide-area warning system for volcanic ash or other hazard sources that can exist for air traffic due to high aerosol pollutions such as forest fires.
In order to survey the volcanic ash pollution above Europe due to the volcanic eruption on the Icelandic Eyjafella Glacier, measurements with the research aircraft of the German Aerospace Center were carried out in April and May of 2010. However, these measurements merely represent samples taken for a limited time and over a limited area. The data acquisition is carried out with the aid of measuring engineers rather than automatically. Subsequently, a time-consuming data evaluation of the measuring results is required on the ground. A fast and accurate warning of civil aviation, for example, about high particle concentrations in case of a nearby volcanic eruption cannot be realized based on the utilization of individual research aircraft. A single research aircraft can hardly survey a moving ash cloud that partly has a length or width of about 1000 km, as well as its exact boundaries, because the smoke cloud continuously changes and aging of the air masses takes place.
Ground-based Lidar systems and satellites are only reliable under cloudless conditions and therefore can frequently not be used as sole data source. However, exact predictions of the dispersion area of a concentrated smoke cloud are required in order to create purposeful no-fly zones. Large-scale no-fly zones resulting from the inaccuracy and the high expenditure of time of today's measuring methods can lead to significant economic losses. It is therefore necessary to provide a simple particle measuring system in order to minimize a restriction of air traffic.
In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.